Tired of walking? Bored with
sitting around? Try hovering! Read the explanation and follow the
links below to find out how this works.

Collect the materials and follow the
instructions to construct your very own super-fast hovercraft!

Safety InformationExperiments are dangerous, but
scientists are always safe!

→Always
have an adult help you collect the materials and conduct the experiment.→Be
careful when you're getting ready to ride the hovercraft. You'll
need one person to hold the craft and help push it. We recommend you sit
on the hovercraft before you put inflate the plastic sheet with the
leafblower. You may also want to add a handle to the hovercraft to
help you stay on. →This
experiment should be performed in a large space, as the hovercraft can
move quickly. →You
should wear a helmet when you're riding the hovercraft, just in case!

Materials

→

Plywood circle 4 ft. diameter, 3/8-1/2
in. thick

→

Heavy plastic sheet, 5 ft x 5 ft

→

Leaf Blower

→

Drill

→

Small plastic disk, like a coffee can lid.

→

Staple gun

→

2 in. Bolt

→

Nut

→

2 fender washers

→

smooth floor

Instructions

1)

2)

3)

Drill a 5/16 inch hole in the exact
center of the plywood circle; the 2 inch bolt should pass through it
easily.

Cut a hole halfway between the center
and the edge of the plywood circle. Draw
the hole first by tracing the mouth of the leafblower.

Lay the plywood disk on the large
plastic sheet, fold the sheet over
the plywood and staple the sheet to
the plywood about every 4 inches using the staple gun. The plastic sheet
should be tight but not too tight. Cut
off the excess plastic and tape the edges down. (picture)

4)

Poke a hole in the center of the
plastic disk. Attach it to the
bottom of the hovercraft, over the plastic sheet, lining up the holes.
Secure it in place by putting the
fender washers on either side of the plywood and then the nut and the
bolt on either side of the fenders.

5)

Cut six 2-inch vent holes in the
plastic around the center of the plywood, within a few inches
ofthe
plastic disk.

6)

Flip the hovercraft over so the
plastic sheet is on the bottom, set
it on the floor, stick the leaf
blower into the hole and turn it on. The plastic will inflate.

Vrooooooooooooooooooooooooom!

Explanation

What would happen if you sat on your plywood circle without the plastic
underneath? Probably nothing. This is because of friction.

When two dry
objects move past one enough there is a force on them called static or
sliding friction. This friction slows the objects down. Imagine
you are sitting on a regular playground slide. You slide down it. Fun,
right? Now imagine you're on a water slide. Why can you go faster
on a water slide? (picture)

On a water
slide, the friction is called "fluid" friction, or drag. Now,
instead of having your body rub against the slide, there is a layer of
water in between you and the slide. This water makes it easier to
move quickly.

When there is
just air between two objects, there is even less drag and more speed.
Have you ever seen an air hockey table? In air hockey, the
hockey puck floats on air that is blowing on the surface of the table.
This is what makes it move so fast across the table. In this experiment,
the hovercraft is just like the hockey puck. The vents in the plastic
sheet allow air to escape from the bottom, just enough to create a thin
layer of air. This reduces the drag and lets your hovercraft
really fly!